Nonresonant referenced laser-induced thermal acoustics thermometry in air

Abstract

We report a detailed investigation of nonresonant laser-induced thermal acoustics (LITA) for the single-shot measurement of the speed of sound (v(S)) in an oven containing room air. A model for the speed of sound that includes important acoustic relaxation effects is used to convert the speed of sound into temperature. A reference LITA channel is used to reduce uncertainties in v(S). Comparing thermocouple temperatures with temperatures deduced from our v(S) measurements and model, we find the mean temperature difference from 300 to 650 K to be 1% (+/-2sigma). The advantages of using a reference LITA channel are discussed.